The present invention relates generally to a force producing apparatus and, more particularly, to an air to oil pressure intensifier for providing relatively large forces to machines such as clamps, grippers, presses and punches.
Many systems utilize the basic principle of inserting a rod into an enclosed oil-filled chamber to produce force. One known system injects a large volume of hydraulic fluid behind a working piston to advance a rod into contact with a work piece. The rod is further inserted into a closed chamber to obtain a force multiplication equal to the ratio of the area of working piston to the area of the end of the rod.
Because large forces are generated by air to oil intensifiers, the working piston is often attached to a tool which may weigh several hundred pounds or more. Returning heavy tools to an elevated or beginning position has become a significant design challenge. Some devices accomplish the task of returning the tool by using an additional piston powered by air. The piston must be of sufficient diameter to produce the requisite force to lift the tool. Devices incorporating external additional pistons are very costly, difficult to package within work cells having limited space and require special air circuits and controls to operate the multiple piston arrangement. These systems are typically large in length and may only be shortened by stacking the units side by side.
Accordingly, it would be beneficial to provide a compact, lightweight pressure intensifier capable of lifting heavy tooling without the use of an external assist cylinder.
A device minimizing the need for external valving and circuit controllers required for operation would also be of benefit.
The present invention provides a pressure intensifier for providing relatively large output forces using an air or hydraulic force amplification system. According to one aspect of the present invention, a rod is driven into a sealed chamber of substantially incompressible fluid to generate an output force.
According to another aspect of the present invention, a compact, lightweight pressure intensifier capable of lifting heavy tooling with the use of an external assist cylinder is provided. According to another aspect of the present invention, a first piston is selectively driven by a fluid power source to retract the piston from a previously force-intensified position.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.